Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Radon-222 monitoring at German ICOS atmosphere stations

Gachkivskyi, Maksym ; Karstens, Ute LU orcid ; Fischer, Bernd ; Kubistin, Dagmar ; Müller-Williams, Jennifer ; Lindauer, Matthias and Levin, Ingeborg (2025) In Earth System Science Data 17(11). p.6173-6197
Abstract

Atmospheric measurements of the short-lived radioactive noble gas radon-222 (222Rn) have many applications. Its concentrations are driven by atmospheric mixing as well as seasonal variations, which follow the seasonality of 222Rn exhalation from continental soils, with lower values during the wet winter and spring months compared to more dry summer conditions. Hence, it can be used as a tracer to distinguish marine from continental air masses or for transport model validation. The Heidelberg Radon Monitor (HRM) is a static filter detector measuring atmospheric 214polonium (214Po), which is a progeny of 222Rn. These measurements can be used to infer atmospheric 222Rn... (More)

Atmospheric measurements of the short-lived radioactive noble gas radon-222 (222Rn) have many applications. Its concentrations are driven by atmospheric mixing as well as seasonal variations, which follow the seasonality of 222Rn exhalation from continental soils, with lower values during the wet winter and spring months compared to more dry summer conditions. Hence, it can be used as a tracer to distinguish marine from continental air masses or for transport model validation. The Heidelberg Radon Monitor (HRM) is a static filter detector measuring atmospheric 214polonium (214Po), which is a progeny of 222Rn. These measurements can be used to infer atmospheric 222Rn activity concentrations if the radioactive disequilibrium between 214Po and 222Rn at the measurement site is known. In this study, 214Po activity concentrations measured with the HRM at eight stations in the Integrated Carbon Observation System (ICOS) Germany network are presented, along with guidelines for evaluating these data to estimate atmospheric 222Rn activity concentrations. In addition to the established line loss and disequilibrium corrections applied when sampling through long tubing or from air intake heights close to the ground, respectively, an upper limit for relative humidity (RH) is suggested, where secular equilibrium can still be assumed. At higher RH, aerosol scavenging effects can cause disequilibrium between 214Po and 222Rn. Using comparison with the model this threshold is determined to be at about 98 % RH and was applied uniformly at all measurement sites. A clear diurnal cycle of 222Rn is observed at all German tower stations during the summer and autumn months as is a seasonal cycle with a maximum during summer and autumn months. Overall, our results demonstrate that the 214Po-based 222Rn measurements with the HRM are reliable if the equilibrium conditions between 214Po and 222Rn can be ensured, i.e., for air intake heights above 80–90 m a.g.l. during conditions with RH < 98 %. The corrected and ready-to-use dataset of 10-year radon activity concentrations from the eight ICOS stations is published alongside this paper (https://doi.org/10.18160/Q2M8-B1HJ, Fischer et al., 2024).

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Radon, Radon progeny
in
Earth System Science Data
volume
17
issue
11
pages
25 pages
publisher
Copernicus GmbH
external identifiers
  • scopus:105022279584
ISSN
1866-3508
DOI
10.5194/essd-17-6173-2025
language
English
LU publication?
yes
additional info
Publisher Copyright: © Author(s) 2025.
id
de419fbc-4949-47e8-8c61-1853c321eda8
date added to LUP
2025-12-02 13:18:28
date last changed
2025-12-02 16:10:21
@article{de419fbc-4949-47e8-8c61-1853c321eda8,
  abstract     = {{<p>Atmospheric measurements of the short-lived radioactive noble gas radon-222 (<sup>222</sup>Rn) have many applications. Its concentrations are driven by atmospheric mixing as well as seasonal variations, which follow the seasonality of <sup>222</sup>Rn exhalation from continental soils, with lower values during the wet winter and spring months compared to more dry summer conditions. Hence, it can be used as a tracer to distinguish marine from continental air masses or for transport model validation. The Heidelberg Radon Monitor (HRM) is a static filter detector measuring atmospheric <sup>214</sup>polonium (<sup>214</sup>Po), which is a progeny of <sup>222</sup>Rn. These measurements can be used to infer atmospheric <sup>222</sup>Rn activity concentrations if the radioactive disequilibrium between <sup>214</sup>Po and <sup>222</sup>Rn at the measurement site is known. In this study, <sup>214</sup>Po activity concentrations measured with the HRM at eight stations in the Integrated Carbon Observation System (ICOS) Germany network are presented, along with guidelines for evaluating these data to estimate atmospheric <sup>222</sup>Rn activity concentrations. In addition to the established line loss and disequilibrium corrections applied when sampling through long tubing or from air intake heights close to the ground, respectively, an upper limit for relative humidity (RH) is suggested, where secular equilibrium can still be assumed. At higher RH, aerosol scavenging effects can cause disequilibrium between <sup>214</sup>Po and <sup>222</sup>Rn. Using comparison with the model this threshold is determined to be at about 98 % RH and was applied uniformly at all measurement sites. A clear diurnal cycle of <sup>222</sup>Rn is observed at all German tower stations during the summer and autumn months as is a seasonal cycle with a maximum during summer and autumn months. Overall, our results demonstrate that the <sup>214</sup>Po-based <sup>222</sup>Rn measurements with the HRM are reliable if the equilibrium conditions between <sup>214</sup>Po and <sup>222</sup>Rn can be ensured, i.e., for air intake heights above 80–90 m a.g.l. during conditions with RH &lt; 98 %. The corrected and ready-to-use dataset of 10-year radon activity concentrations from the eight ICOS stations is published alongside this paper (https://doi.org/10.18160/Q2M8-B1HJ, Fischer et al., 2024).</p>}},
  author       = {{Gachkivskyi, Maksym and Karstens, Ute and Fischer, Bernd and Kubistin, Dagmar and Müller-Williams, Jennifer and Lindauer, Matthias and Levin, Ingeborg}},
  issn         = {{1866-3508}},
  keywords     = {{Radon; Radon progeny}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{11}},
  pages        = {{6173--6197}},
  publisher    = {{Copernicus GmbH}},
  series       = {{Earth System Science Data}},
  title        = {{Radon-222 monitoring at German ICOS atmosphere stations}},
  url          = {{http://dx.doi.org/10.5194/essd-17-6173-2025}},
  doi          = {{10.5194/essd-17-6173-2025}},
  volume       = {{17}},
  year         = {{2025}},
}